feat(kubernetes): Surface Image Pull Errors in Kubernetes Runtime

[cognifloyd]

The Docker Runtime surfaces image pull errors naturally because of the blocking synchronous requests to pull an image or start a container.
Kubernetes is asynchronous, so we have to explicitly watch for events to make sure the image pull succeeds in RunContainer.
When we capture a failure event, we can surface the event in the same way as the Docker runtime.

There may be other places where we need to watch for events, so I extracted some of the test logic from WaitContainer to make it reusable.

Also, this changes the init step so it says "Preparing" instead of "Pulling" since the Kubernetes runtime does NOT pull during init.

• Replace "Pulling" with "Preparing" in init step logs
• More image validation in kubernetes runtime
• Rename watch->podWatch for planned imports
• Extract Kubernetes Client + Watch mocking logic
• Escape selector just in case
• Move newMockWithWatch to kubernetes_test.go
• Close the podWatch in WaitContainer
• Enhance RunContainer to watch for image pull events
• Add RunContainer image pull failure test

[codecov]

Codecov Report

Merging #279 (3df89d0) into master (c1d4563) will decrease coverage by 0.13%.
The diff coverage is 67.05%.

@@            Coverage Diff             @@
##           master     #279      +/-   ##
==========================================
- Coverage   78.91%   78.77%   -0.14%     
==========================================
  Files          67       67              
  Lines        4870     4952      +82     
==========================================
+ Hits         3843     3901      +58     
- Misses        884      903      +19     
- Partials      143      148       +5     

Impacted Files	Coverage Δ
runtime/kubernetes/image.go	65.62% <62.50%> (+13.62%)	⬆️
runtime/kubernetes/container.go	75.21% <67.53%> (-2.40%)	⬇️

[kneal]

LGTM 🐬

[wass3r]

thank you!

[wass3r]

can you please fix up the new linting errors? we added/modified some rules that triggered a few issues.

[cognifloyd]

I'm really not sure what to do to replace context.Background() for the k8s no API requests. The other instances were skipped, stop that's what I did. Is there a better way?

[cognifloyd]

I'm going to break this down into more discrete PRs. As I'm studying issues with the k8s runtime, I'm considering some different ways to subscribe to the event stream related to a build.

[cognifloyd]

Closing in favor of #331